constant member functions

[srinivas reddy]

Hi,
Can a constant member function be overloaded with its non-constant
equivalent. I mean can void func() be overloaded with void func()
const. If so what behaviour is guaranteed, how does the compiler
resolve ambiguity?, and how could I call a specific variant?

tia,
Srinivas

 

[Victor Bazarov]

Can a constant member function be overloaded with its non-constant
equivalent.

If that's a question (somehow I got used to seeing '?' at
the ends of questions), then the aswer is 'yes'.

I mean can void func() be overloaded with void func()
const.
Yes.

If so what behaviour is guaranteed, how does the compiler
resolve ambiguity?

There is no ambiguity. Non-const function is preferred when
called for a non-const object. For a const object non-const
function cannot be called.

, and how could I call a specific variant?

By using a cons_cast if the const-ness of the function is
not to your satisfaction. However, casting away const and
then calling a non-const function for a const object will
result in undefined behaviour.

Victor

 

[Andrey Tarasevich]

...
Can a constant member function be overloaded with its non-constant
equivalent. I mean can void func() be overloaded with void func()
const.
Yes.

If so what behaviour is guaranteed, how does the compiler
resolve ambiguity?, and how could I call a specific variant?
...

For overloading purposes, you can think of member functions as if they
are ordinary functions with an additional implicit 'this' parameter.
When declared as a member of class 'A', method 'void func()' is
equivalent to standalone function 'void func(A* this)' and method 'void
func() const' is equivalent to standalone function 'void func(const A*
this)'. The overloading will work the same way it works for standalone
functions. For non-constant object the first version is called, for
constant objects the second version is called.